Tuberculosis Disease Among Adults Aged 65 Years and Older: Alameda County, California, 2016-2019

Older adults aged ≥65 years old represent an increasing proportion of tuberculosis (TB) cases in the United States, but limited evidence exists on the characteristics and treatment outcomes that differentiate them from younger adults.

We evaluated Alameda County TB surveillance data from 2016 to 2019 and abstracted public health charts for older adult TB cases. Clinical presentation and treatment outcomes were compared in older and younger adults (15-64 years), and multivariable logistic regression was conducted to assess risk factors for TB treatment noncompletion among older adults.

Of 517 TB cases, 172 (33.2%) were older adults and 101 were ≥75 years old. Compared to younger adults, older TB cases were more likely to be non-US-born, and have diabetes. For diagnosis, older adults were more likely to have negative interferon-gamma release assays (24.6% vs 16.0%; P = .01) and were less likely to have cavitary disease (18.6% vs 26.7%; P < .001). One third of older adults experienced an adverse event; older adults were less likely to complete TB treatment (77.7% vs 88.4%; P = .002) and were more likely to die during TB treatment (16.3% vs 2.9%; P < .01), especially among those ≥75 years old, who had a mortality rate of 22.9%. In multivariable analysis, dementia was significantly associated with treatment noncompletion (adjusted odds ratio, 5.05; 95% confidence interval, 1.33-20.32; P = .02).

Diabetes, negative diagnostic tests, and poor treatment outcomes were more prevalent in older adult TB cases. A greater understanding of their TB presentation and comorbidities will inform interventions to improve outcomes among older adults.